Well I've got the solution: a lovely little site called Grooveshark, where you can search for artists and songs, add them to your library, create playlists, etc. They have just about anything you can think of and, unlike Pandora (which I do also love and has its own perks), there are no commercials. Oh, hey; did I mention it's free?!
What I'm Listening too on Grooveshark right now: